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R. N 508 858. Pat d Nov. 14 189 7 @Y x. @J7 v vx v j? Z l|lNllllllhllllllilllllIllillllllmlil" k W mmunuunuumummuuiu. E

MINIMUM i UNITED STATESl VPATENT OFFICE.

JAMES S. BACK, OF OTTAWA, CANADA, ASSIGNCR OF ONE-HALF TO GEORGE LEWIS ORME, OF SAME PLACE.

GUITAR.

SPECIFICATION forming part of Letters Patent No. 508,858, dated November 14,1893.

Application led August 22,1893.

To a/Z whom t may concern.-

Be it known that I, JAMES S. BACK, of the city of Ottawa, in the county of Carleton and Province ot' Ontario, in the Dominion of Canada, have invented certain new and useful Improvelnents in Guitars; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming a part hereof.

My invention, which will be hereinafter fully set forth and claimed, relates to guitars, and other similar instruments.

The objects of my invention are to strengthen the belly of the instrument and prevent it warping from the strain of the strings on the bridge; to increase the volume of sound and strength of tone and to strengthen the neck attachment. I attain these objects by means of a raised longitudinal belly ridge, a double inclined sound-board in a separate rim and making the sound holes high up near the neck and by a post or pin in the cross grained end of the neck.

Figure lisa section of the improved guitar taken on line a; oc, Figs. 2, 3, 4t and 5, transversely through the rim, a little below the ybelly and showing the sound-board in top view, the two being distinguished by tinting lines running in different directions. Fig. 2 is a longitudinal section of the same on line y y, Figs. l, 3, 4 and 5. Fig. 3 is a transverse section of the shell on line e a', Figs. l and 2.

Fig. 4. is a transverse section of the shell on line z' e', Figs. 1 and 2, and Fig. 5 is a transverse section of the shell on line e z", Figs. 1 and 2.

The shell, as usual, is constructed of a rim A to which, by means of continuous corner blocks a, the belly B with ribs B and back C with ribs C', are secured and which is connected by the end blocks A and A.

The belly is constructed with a raised ridge or transverse swelling b, about a quarter of an inch high and running from end to end, shown in cross section in Figs. 3, 4 and 5, the the ribs B being shaped to correspond, deep in the center and tapering toward the ends. The bridge, E, is secured to the belly in the 5o usual way, being shaped to the ridge b. The

Serial IIe-483,777. (Nomodel.)

end d, of the neck, D, as usual, is dovetailed in the end block A and in order to strengthen said end, which runs across the grain of the wood, a pin D is driven into it. F, Fig. 2, is the fingerboard, secured to the neck, as usual.

Vtithin the shell is secured a double soundboard G I-I, held by continuous corner blockst' in a separate narrow rim I secured at each end to the end blocks A and A and not touching the rim A but running close to it; each board being provided with ribs g and h respectively. The top or upper board runs from a point 2 about under\the end of the linger board and close to the belly to thepoint 3 within a short distance of the end block A and gradually sloping away from the belly to about midway between it and the back, at which point the lower one I-I is connected to the upper one and starts running toward the neck block to a point 4 within a short distance of it, but passing the edge of the upper one and also sloping a little toward the belly, so that the distance between the back and the upper end (at the point 4) is greater than between it and the lower end (at the point 3). The sound holes b' are placed above the upper edge of the upper sound-board G and partly over the upper edge of the lower one.

It may be remarked that the ridge b imparts stiffness to the belly iu the direction of the strain produced by the strings, that the sound-boards strengthen the tone and their sloping position causing the sound waves to travel downward around the lower edge then upward around the upper edge of the lower one and out of the sound-holes l?. These improvements are described as applied to a guitar but the raised ridge and sound*board are equally applicable to bandolins, mandoline and other` similar instruments.

I claim as my invention l. In combination with the belly of a guitar or similar instrument, a ridge consisting of a transverse swelling extending longitudinally from end to end, substantially as set forth.

2. The combination with the shell of a guiM tar or similar instrument, a double' soundboard consisting of two converging parts of dierent lengths united aty one end, the longest part shorter than the distance between IOO the two end blocks and placed about midway between them so that the united end is nearer the tail end and about midway between the belly and the back and the upper single end nearer the belly and said sound-boards held in a narrow rim secured to the end blocks, substantially as set forth.

3. The combination with the neck of aguitar, a pin D driven across the grain of the wood, substantially as set forth.

4. The combination with the shell A B C and blocks A' and A, of the sound-boards Gr and H converging to an edge and each pro vided with transverse ribs, a narrow liml secured to the end blocks A' A and holding said sound-boards, and the sound holes b in the belly B near the neck over the open end of said SOundbOard, substantially as set forth.

In testimony whereof I have signed my name in the presence of the undersigned witnesses.

JAS. S. BACK.

Witnesses:

A. HARVEY, B. HARVEY. 

